diff --git a/app.js b/app.js
index ad9a93a..f82c18c 100644
--- a/app.js
+++ b/app.js
@@ -1 +1,17 @@
 'use strict';
+const memo = new Map();
+memo.set(0,0);
+memo.set(1,0);
+memo.set(2,1);
+function trib(n) {
+  if (memo.has(n)) {
+    return memo.get(n);
+  }
+  const value = trib(n-1) + trib(n - 2) + trib(n - 3);
+  memo.set(n, value);
+  return value;
+}
+const length = 40;
+for (let i = 0; i <= length; i++) {
+  console.log(trib(i));
+}